## getgrent
while( ($name,$passwd,$gid,$members) = getgrent() ) {
   print "Name = $name\n";
   print "Password = $passwd\n";
   print "GID = $gid\n";
   print "Members = $members\n";
}

## setgrent
setgrent();

## endgrent
endgrent();

@addrbytes = (192,168,0,1);
$packedaddr = pack("C4", @addrbytes);
($name, $altnames, $addrtype, $addr) = getnetbyaddr($packedaddr, AF_NET);

Note: the address passed to getnetbyaddr must be a packed 4 byte integer, see pack for more information regarding packing

setnetent(<keepopen>);    ## keep open the networks file after getnetbyaddr or getnetbyname is
                          ## called

endnetent;                ## clode the /etc/networks file

## gethostent
($name, $altnames, $addrtype, $len $addr) = gethostent();

## sethostent
sethostent(<keepopen>);

## endhostent
endhostent();

## getpgrp
$prgroup = getpgrp(<pid>);

## setpgrp
setpgrp (<pid>,<grouppid>);

## getpwent
($name, $passwd, $uid, $gid, $quota, $comment, $gcos, $dir, $shell) = getpwent();

## setpwent
setpwent(<keepopen>);

## endpwent
endpwent();

## getpriority
($username, password, $userid) = getpwnam("pvalle");
$current_priority = getpriority(2, $userid);

## setpriority
setpriority(2, $userid, $current_priority + 1);

## setprotoent
setprotoent(<keepopen>);

## endprotoent
endprotoent();

## getservbyname
($name, $aliases, $portnum, $protoname) = getservbyname(<searchname>,<searchproto>););

## getservbyport
($name, $aliases, $portnum, $protoname) = getservbyport(<searchportnum>,<searchproto>););

## setservent
setservent(<keepopen>);

## endservent
endservent();

## A simple server program
$line = "Hello World\n";

$port = 8888;

while (getservbyport ($port, "tcp")) {
   $port++;
}

($d1, $d2, $prototype) = getprotobyname("tcp");
($d1, $d2, $d3, $d4, $rawserver) = gethostbyname("xblade");

$serveraddr = pack("Sna4x8", 2, $port, $rawserver);

socket (SSOCKET, 2, 1, $protoype) || die("ERROR: unable to open socket\n");
bind (SSOCKET, $serveraddr) || die("ERROR: unable to bind to socket\n");
listen (SSOCKET, 1) || die("ERROR: unable to listen on socket\n");

($clientaddr = accept (SOCKET, SSOCKET)) || die("ERROR: unable to accept\n");

select(SOCKET);
$| = 1 ;
print SOCKET ("$line\n");
close(SOCKET);
close(SSOCKET);

## A simple client program
$port = 8888;

while (getservbyport ($port, "tcp")) {
   $port++;
}

($d1, $d2, $prototype) = getprotobyname("tcp");
($d1, $d2, $d3, $d4, $rawclient) = gethostbyname("mercury");
($d1, $d2, $d3, $d4, $rawserver) = gethostbyname("xblade");

$clientaddr = pack("Sna4x8", 2, $port, $rawclient);
$serveraddr = pack("Sna4x8", 2, $port, $rawserver);

socket (SOCKET, 2, 1, $protoype) || die("ERROR: unable to open socket\n");
bind (SOCKET, $clientaddr) || die("ERROR: unable to bind to socket\n");
connect (SOCKET, $serveraddr) || die("ERROR: unable to listen on socket\n");

$line = <SOCKET>;
print("$line\n");
close(SOCKET);

shutdown (SOCKET, <direction>);

Note : direction can be either 0, 1, 2
0 - indicates that the program can send through the socket but can no longer receive data
1 - indicates that the program can receive data from the socket but can no longer send
2 - indicates that both sending and receiving are disallowed

## Local computer's socket address
$rawaddr = getsockname(<socket>);
($d1, $d2, @addrbytes) = unpack("SnC4x8", $rawaddr);
$readable = join(".", @addrbytes);

## Remotes computer's socket address
$rawaddr = getpeername(<socket>);
($d1, $d2, @addrbytes) = unpack("SnC4x8", $rawaddr);
$readable = join(".", @addrbytes);